In general as LP/MIP solvers become more sophisticated often their logs become more unfathomable. E.g. back in the old days when primal Simplex LP solvers, the sum of infeasibilities and the objective were good indicators of progress. Nowadays with dual simplex being the default algorithm, numbers just go up and down. With the MIP log, the columns I pay attention to most are lower- and upper-bound and the gap.

(The number of generals is still increasing). It is somewhat difficult to say (the performance of Cplex – and probably other MIP solvers – is a little bit erratic on this model) but it seems that doubling the number of integer variable does not have a major effect.